<body><div><figure><img src="https://img.particlenews.com/image.php?type=thumbnail_580x000&amp;url=0fvoMs_0wPqqyem00" alt="https://img.particlenews.com/image.php?url=0fvoMs_0wPqqyem00" width="1600" height="900" ></figure>If you know anything about <a href="https://www.extremetech.com/tag/black-holes">black holes</a>, it's that they have extraordinary gravitational pull, drawing in distant objects and devouring them. Unsurprisingly, many black holes have stellar companions trapped in tight orbits, but perhaps counterintuitively, astronomers have never seen a triple system with a black hole—until now. Scientists from MIT and Caltech have spotted what is believed to be the first system with a black hole and two stable orbiting companions. The black hole in question is known as V404 Cygni, which is somewhat famous among dead stars. This object, about 8,000 light-years away from Earth, was surveyed in 1992 and confirmed as one of the first known black holes. It has gotten plenty of attention since then, being mentioned in more than 1,300 scientific papers. However, no one noticed its stellar companion until lead author Kevin Burdge of <a href="https://www.extremetech.com/tag/mit">MIT</a> spotted something unexpected buried in a repository of astronomical data. Burdge says he was paging through data in the Aladin Lite database in search of new black holes when he decided to take a peek at V404 Cygni. In one optical image of V404, Burdge noticed two small blobs. One was the black hole's known companion, a star that rockets around it every 6.5 Earth days in such a tight orbit that the black hole strips material from its surface. The other was much more distant—the previously unseen second companion. Using the ESA's Gaia star mapping project, the team confirmed this second star is gravitationally bound to V404 Cygni. The two stars orbit in tandem, according to the Gaia data. The odds of this arrangement being a coincidence are about one in ten million. So, this is almost certainly a triple system, but the outer star's orbit is extremely wide. It's about 3,500 AU from the black hole (1 AU is the distance between Earth and the Sun), and a single orbit takes roughly 70,000 years. <figure><img src="https://img.particlenews.com/image.php?type=thumbnail_580x000&amp;url=0aSerB_0wPqqyem00" alt="https://img.particlenews.com/image.php?url=0aSerB_0wPqqyem00" width="670" height="377" ></figure>This perplexing arrangement raises questions about how V404 Cygni formed. Black holes are believed to form from the <a href="https://www.extremetech.com/science/what-is-a-black-hole">collapse of giant stars</a> at the end of their main sequence lifecycles, a process accompanied by a massive explosion known as a <a href="https://www.extremetech.com/science/explained-what-is-a-supernova">supernova</a>. However, <a href="https://www.nature.com/articles/s41586-024-08120-6">the study</a> found a supernova should have pushed the outer star away from the black hole's tenuous influence. "We think most black holes form from violent explosions of stars, but this discovery helps call that into question," <a href="https://news.mit.edu/2024/physicists-discover-first-black-hole-triple-1023">says</a> Burdge.The team ran thousands of simulations to try and understand how a triple star system could survive when one of them became a black hole. The most likely explanation is that V404 Cygni formed via direct collapse, where a star becomes a black hole without an associated energy release. This process, if it even occurs, is still poorly understood. With this knowledge of V404 Cygni's companions, further study could shed new light on black hole formation. </div></body>

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Astronomers Identify First-Ever Black Hole Triple System

If you know anything about black holes, it's that they have extraordinary gravitational pull, drawing in distant objects and devouring them. Unsurprisingly, many black holes have stellar companions trapped in tight orbits, but perhaps counterintuitively, astronomers have never seen a triple system with a black hole—until now. Scientists from MIT and Caltech have spotted what is believed to be the first system with a black hole and two stable orbiting companions.